Buggy code:
public static final String GET = "GET" ; public static final String OPTIONS = "OPTIONS" ; public static final String TRACE = "TRACE" ; public static final String DELETE = "DELETE" ; public static final String DEFAULT_METHOD = "GET" ; private static final String [ ] METHODS = new String [ ] { HTTPSamplerBase . DEFAULT_METHOD , HTTPSamplerBase . POST , HTTPSamplerBase . HEAD , HTTPSamplerBase . PUT , HTTPSamplerBase . OPTIONS , HTTPSamplerBase . TRACE , HTTPSamplerBase . DELETE } ; public static final List METHODLIST = Collections . unmodifiableList ( Arrays . asList ( HTTPSamplerBase . METHODS ) ) ; public static final String USE_KEEPALIVE = "HTTPSampler.use_keepalive" ; public static final String FILE_NAME = "HTTPSampler.FILE_NAME" ; public static final String DO_MULTIPART_POST = "HTTPSampler.DO_MULTIPART_POST" ; public static final String FILE_FIELD = "HTTPSampler.FILE_FIELD" ; public static final String FILE_DATA = "HTTPSampler.FILE_DATA" ; public static final String FILE_MIMETYPE = "HTTPSampler.FILE_MIMETYPE" ; public static final String CONTENT_TYPE = "HTTPSampler.CONTENT_TYPE" ; public static final String NORMAL_FORM = "normal_form" ; public static final String MULTIPART_FORM = "multipart_form" ; public static final String IMAGE_PARSER = "HTTPSampler.image_parser" ; public static final String EMBEDDED_URL_RE = "HTTPSampler.embedded_url_re" ; public static final String MONITOR = "HTTPSampler.monitor" ; public static final int UNSPECIFIED_PORT = 0 ; public static final String UNSPECIFIED_PORT_AS_STRING = "0" ; protected static final String NON_HTTP_RESPONSE_CODE = "Non<seq2seq4repair_space>HTTP<seq2seq4repair_space>response<seq2seq4repair_space>code" ; protected static final String NON_HTTP_RESPONSE_MESSAGE = "Non<seq2seq4repair_space>HTTP<seq2seq4repair_space>response<seq2seq4repair_space>message" ; private static final String ARG_VAL_SEP = "=" ; private static final String QRY_SEP = "&" ; private static final String QRY_PFX = "?" ; protected static final int MAX_REDIRECTS = JMeterUtils . getPropDefault ( "httpsampler.max_redirects" , 5 ) ; protected static final int MAX_FRAME_DEPTH = JMeterUtils . getPropDefault ( "httpsampler.max_frame_depth" , 5 ) ; protected static final String HEADER_AUTHORIZATION = "Authorization" ; protected static final String HEADER_COOKIE = "Cookie" ; protected static final String HEADER_CONNECTION = "Connection" ; protected static final String CONNECTION_CLOSE = "close" ; protected static final String KEEP_ALIVE = "keep-alive" ; protected static final String TRANSFER_ENCODING = "transfer-encoding" ; protected static final String HEADER_CONTENT_ENCODING = "content-encoding" ; protected static final String HTTP_1_1 = "HTTP//1.1" ; protected static final String HEADER_SET_COOKIE = "set-cookie" ; protected static final String ENCODING_GZIP = "gzip" ; protected static final String HEADER_CONTENT_DISPOSITION = "Content-Disposition" ; protected static final String HEADER_CONTENT_TYPE = "Content-Type" ; protected static final String HEADER_CONTENT_LENGTH = "Content-Length" ; protected static final String HEADER_LOCATION = "Location" ; public static final String APPLICATION_X_WWW_FORM_URLENCODED = "application//x-www-form-urlencoded" ; public static final String MULTIPART_FORM_DATA = "multipart//form-data" ; private static Map parsersForType = new HashMap ( ) ; private static final String RESPONSE_PARSERS = JMeterUtils . getProperty ( "HTTPResponse.parsers" ) ; private boolean dynamicPath = false ; public HTTPSamplerBase ( ) { } public void setFileField ( String value ) { } public String getFileField ( ) { } public void setFilename ( String value ) { } public String getFilename ( ) { } public boolean getSendFileAsPostBody ( ) { } public boolean getSendParameterValuesAsPostBody ( ) { } public boolean getUseMultipartForPost ( ) { } public void setProtocol ( String value ) { } public String getProtocol ( ) { } public void setPath ( String path ) { } public String getPath ( ) { } public void setFollowRedirects ( boolean value ) { } public boolean getFollowRedirects ( ) { } public void setAutoRedirects ( boolean value ) { } public boolean getAutoRedirects ( ) { } public void setMethod ( String value ) { } public String getMethod ( ) { } public void setContentEncoding ( String value ) { } public String getContentEncoding ( ) { } public void setUseKeepAlive ( boolean value ) { } public boolean getUseKeepAlive ( ) { } public void setDoMultipartPost ( boolean value ) { } public boolean getDoMultipartPost ( ) { } public void setMonitor ( String value ) { } public void setMonitor ( boolean truth ) { <START_BUG> this . setProperty ( HTTPSamplerBase . MONITOR , JOrphanUtils . booleanToString ( truth ) ) ; <END_BUG> } public String getMonitor ( ) { } public boolean isMonitor ( ) { } public void setImplementation ( String value ) { } public String getImplementation ( ) { } public void addEncodedArgument ( String name , String value ) { } public void addEncodedArgument ( String name , String value , String metaData ) { } public void addNonEncodedArgument ( String name , String value , String metadata ) { } public void addArgument ( String name , String value ) { } public void addArgument ( String name , String value , String metadata ) { } public void addTestElement ( TestElement el ) { } public void setPort ( int value ) { } public static int getDefaultPort ( String protocol , int port ) { } public boolean isProtocolDefaultPort ( ) { } public int getPort ( ) { } public void setDomain ( String value ) { } public String getDomain ( ) { } public void setArguments ( Arguments value ) { } public Arguments getArguments ( ) { } public void setAuthManager ( AuthManager value ) { } public AuthManager getAuthManager ( ) { } public void setHeaderManager ( HeaderManager value ) { } public HeaderManager getHeaderManager ( ) { } public void setCookieManager ( CookieManager value ) { } public CookieManager getCookieManager ( ) { } public void setMimetype ( String value ) { } public String getMimetype ( ) { } public boolean isImageParser ( ) { } public void setImageParser ( boolean parseImages ) { } public String getEmbeddedUrlRE ( ) { } public void setEmbeddedUrlRE ( String regex ) { } protected HTTPSampleResult errorResult ( Throwable e , HTTPSampleResult res ) { } public java . net . URL getUrl ( ) throws MalformedURLException { } public String getQueryString ( ) { } public String getQueryString ( String contentEncoding ) { } public void parseArguments ( String queryString ) { } public String toString ( ) { }

Fix:
this . setProperty ( HTTPSamplerBase . MONITOR , truth ) ;